deps: patch V8 to support compilation with MSVC

Co-Authored-By: Michaël Zasso <[email protected]>

Author: StefanStojanovic

common.gypi

@@ -37,7 +37,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.3',
+    'v8_embedder_string': '-node.4',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/src/compiler/js-heap-broker.cc

@@ -879,7 +879,7 @@ ElementAccessFeedback const& JSHeapBroker::ProcessFeedbackMapsForElementAccess(
     Tagged<Map> transition_target;
 
     // Don't generate elements kind transitions from stable maps.
-    if (!map.is_stable()) {
+    if (!map.is_stable() && possible_transition_targets.begin() != possible_transition_targets.end()) {
       // The lock is needed for UnusedPropertyFields (called deep inside
       // FindElementsKindTransitionedMap).
       MapUpdaterGuardIfNeeded mumd_scope(this);

deps/v8/src/execution/frames.h

@@ -1292,11 +1292,11 @@ class WasmFrame : public TypedFrame {
   FrameSummaries Summarize() const override;
 
   static WasmFrame* cast(StackFrame* frame) {
-    DCHECK(frame->is_wasm()
 #ifdef V8_ENABLE_DRUMBRAKE
-           && !frame->is_wasm_interpreter_entry()
+    DCHECK(frame->is_wasm() && !frame->is_wasm_interpreter_entry());
+#else
+    DCHECK(frame->is_wasm());
 #endif  // V8_ENABLE_DRUMBRAKE
-    );
     return static_cast<WasmFrame*>(frame);
   }
 

deps/v8/src/execution/isolate.h

@@ -563,10 +563,14 @@ using DebugObjectCache = std::vector<Handle<HeapObject>>;
 #define THREAD_LOCAL_TOP_ADDRESS(type, name) \
   inline type* name##_address() { return &thread_local_top()->name##_; }
 
+#if defined(_MSC_VER)
+extern thread_local Isolate* g_current_isolate_ V8_CONSTINIT;
+#else
 // Do not use this variable directly, use Isolate::Current() instead.
 // Defined outside of Isolate because Isolate uses V8_EXPORT_PRIVATE.
 __attribute__((tls_model(V8_TLS_MODEL))) extern thread_local Isolate*
     g_current_isolate_ V8_CONSTINIT;
+#endif  // defined(_MSC_VER)
 
 // HiddenFactory exists so Isolate can privately inherit from it without making
 // Factory's members available to Isolate directly.

deps/v8/src/heap/local-heap.h

@@ -34,10 +34,14 @@ class MarkingBarrier;
 class MutablePageMetadata;
 class Safepoint;
 
+#if defined(_MSC_VER)
+extern thread_local LocalHeap* g_current_local_heap_ V8_CONSTINIT;
+#else
 // Do not use this variable directly, use LocalHeap::Current() instead.
 // Defined outside of LocalHeap because LocalHeap uses V8_EXPORT_PRIVATE.
 __attribute__((tls_model(V8_TLS_MODEL))) extern thread_local LocalHeap*
     g_current_local_heap_ V8_CONSTINIT;
+#endif  // defined(_MSC_VER)
 
 // LocalHeap is used by the GC to track all threads with heap access in order to
 // stop them before performing a collection. LocalHeaps can be either Parked or

deps/v8/src/objects/tagged-field.h

@@ -121,12 +121,10 @@ static_assert(sizeof(UnalignedDoubleMember) == sizeof(double));
 #define FLEXIBLE_ARRAY_MEMBER(Type, name)                     \
   using FlexibleDataReturnType = Type[0];                     \
   FlexibleDataReturnType& name() {                            \
-    static_assert(alignof(Type) <= alignof(decltype(*this))); \
     using ReturnType = Type[0];                               \
     return reinterpret_cast<ReturnType&>(*(this + 1));        \
   }                                                           \
   const FlexibleDataReturnType& name() const {                \
-    static_assert(alignof(Type) <= alignof(decltype(*this))); \
     using ReturnType = Type[0];                               \
     return reinterpret_cast<const ReturnType&>(*(this + 1));  \
   }                                                           \

deps/v8/src/wasm/wasm-objects.cc

@@ -2739,15 +2739,21 @@ Handle<WasmExportedFunction> WasmExportedFunction::New(
     DirectHandle<WasmFuncRef> func_ref,
     DirectHandle<WasmInternalFunction> internal_function, int arity,
     DirectHandle<Code> export_wrapper) {
+#if V8_ENABLE_DRUMBRAKE
   DCHECK(CodeKind::JS_TO_WASM_FUNCTION == export_wrapper->kind() ||
          (export_wrapper->is_builtin() &&
           (export_wrapper->builtin_id() == Builtin::kJSToWasmWrapper ||
-#if V8_ENABLE_DRUMBRAKE
            export_wrapper->builtin_id() ==
                Builtin::kGenericJSToWasmInterpreterWrapper ||
-#endif  // V8_ENABLE_DRUMBRAKE
            export_wrapper->builtin_id() == Builtin::kWasmPromising ||
            export_wrapper->builtin_id() == Builtin::kWasmStressSwitch)));
+#else
+  DCHECK(CodeKind::JS_TO_WASM_FUNCTION == export_wrapper->kind() ||
+         (export_wrapper->is_builtin() &&
+          (export_wrapper->builtin_id() == Builtin::kJSToWasmWrapper ||
+           export_wrapper->builtin_id() == Builtin::kWasmPromising ||
+           export_wrapper->builtin_id() == Builtin::kWasmStressSwitch)));
+#endif  // V8_ENABLE_DRUMBRAKE
   int func_index = internal_function->function_index();
   Factory* factory = isolate->factory();
   DirectHandle<Map> rtt;